This invention relates to an ink fountain device for continuously supplying printing ink of a predetermined quantity to a printing press.
An ink fountain for supplying printing ink to a platen mounted on a platen roller of a rotary printing press generally comprises an ink fountain device for dispensing the ink stored in an ink pot at a predetermined rate and a plurality of groups of rollers which transfer the dispensed ink to the surface of the platen and makes uniform the thickness of the ink film transferred to the platen. The ink fountain device has been constructred as shown in FIG. 1 where beneath a fountain roller 1 which is rotated in the direction of arrow A are provided stays 2 and 3 having substantially the same length as the longitudinal length of the roller 1, with an inclined blade support 4 having the same length as the stay 2 is mounted thereon by bolts 5. A fountain blade 6 made of a thin steel plate and having the same length as the blade support 4 is bolted onto the upper surface thereof with its inner end closely adjacent to the periphery of the fountain roller 1, and vertical triangular side plates 7 are secured to the opposite sides of the blade support 4. A plurality of L shaped adjusting pieces 8 are pivotally mounted on the top of the other stay 3 with equal spacings of 20 to 50 mm, for example, respective adjusting pieces 8 being adjusted by corresponding adjusting screws 9. The printing ink 10 is stored in an ink pot defined by the fountain roller 1, the fountain blade 6 and both side plates 7. As the fountain roller 1 rotates, the ink 10 flows out through a gap between the fountain roller 1 and the fountain blade 6 so as to form a thin ink film on the surface of the fountain roller 1. The thickness of this ink film, that is the quantity of the ink supplied to the platen is adjusted by adjusting the adjusting screws 9 so as to elastically deform the fountain blade 6 for adjusting the gap between the tip of the fountain blade 6 and the periphery of the fountain roller 1. The quantity of the ink can be individually adjusted in respective sections of the fountain roller 1 obtained by dividing the same in the axial direction, by independently adjusting the adjusting screws 9 thereby adjusting the quantity of the ink in accordance with the contrast of printed matters.
However, in the prior art ink fountain device of the type described above, the fountain blade 6 is constructed as a single blade. Thus where it is desired to decrease the quantity of the ink at portions corresponding to adjusting scres 9A and 9B on both sides and to increase the quantity of ink at an intermediate portion corresponding to an intermediate adjusting screw 9C as shown in FIG. 2, even when the intermediate adjusting screw 9C is retracted while the adjusting screws 9A and 9B are maintained in their advanced states, the fountain blade 6 would maintain its state determined by the adjusting screws 9A and 9B on both sides and responds to the retraction of the adjusting screw 9C. Accordingly, it has been necessary to retract the adjusting screws 9A and 9B slightly on both sides, which results in a rough adjustment as shown in FIG. 3. Moreover, advance of a single adjusting screw has an influence on both sides thereof thus comprising the accuracy of adjustment.
To obviate these problems it has been proposed to use a divided fountain blade system in which the fountain blade is divided into a plurality of sections in the axial direction of the fountain roller 1. However in such divided fountain blade systems, it is necessary to vary the thickness of the ink film for respective blade sections and moreover it is necessary not only to adjust the sections at high accuracies but also to be able to adjust the sections from a remote position. Moreover since it is necessary to frequently dismount the divided sections for maintainence, washing and color change, it is necessary to separately prepare the blade sections and their adjusting mechanisms and then assemble them. However, prior art divided fountain blade systems cannot satisfy these requirements so that it has been highly desired to develope and improved ink fountain device.